The aid worker, who has not yet been named, was seized late Saturday afternoon by armed men around 30 kilometers outside the Red Sea port city of Hudaida, an ICRC spokeswoman told the Agence France Presse Sunday.

“We haven’t had any contact with his captors. We are very concerned for his health and well-being,” Marie-Servane Desjonqueres said, adding: “We are hoping for his immediate and unconditional release.”

Two Yemeni drivers accompanying the man were also captured, but were released shortly after. The Red Cross office in the capital, Sana’a, said the French official had been working in the northern city of Saada, according to the BBC.